Low-torque sliding components have sliding surfaces rotated relative to each other with an annular mating ring and an annular seal ring facing each other. The sliding surface of at least one of the mating ring and the seal ring has therein a plurality of multi-stepped recess portions formed in a circumferential direction. Relative rotation and sliding of the mating ring and the seal ring causes the multi-stepped recess portions to generate a dynamic pressure, and the multi-stepped recess portion is formed in a stepwise shape in a cross-sectional view by a dynamic pressure recess portion and a static pressure recess portion with the dynamic pressure recess portion surrounding the static pressure recess portion deeper than the dynamic pressure recess portion.

In an annular sliding component disposed at a relatively rotating position of a rotating machine and sliding relative to an opposed sliding component, a sliding surface is provided with a plurality of first dynamic pressure generation grooves disposed on a leakage side, having terminating ends, and generating a positive pressure and a plurality of second dynamic pressure generation grooves disposed on a sealing target fluid side, having terminating ends, and generating a positive pressure and a depth of the second dynamic pressure generation groove is shallower than a depth of the first dynamic pressure generation groove.

In a sliding component formed in an annular shape and disposed at a relatively rotating position of a rotating machine and sliding relative to an opposite sliding component, a sliding surface of the sliding component is provided with a conduction groove communicating with an outer space and a dynamic pressure generation groove communicating with the conduction groove, extending in a circumferential direction, and having a closed terminating end portion and at least a part of a bottom portion of the conduction groove is provided with an inclined surface inclined with respect to a radial direction.

A sliding surface of a second sliding component is provided with a plurality of second positive pressure generation grooves communicating with a leakage side space, extending in a relative rotation direction of the second sliding component, and having closed terminating end portions, a sliding surface of a first sliding component is provided with a plurality of first positive pressure generation grooves communicating with the leakage side space, extending in a relative rotation direction of the second sliding component, and having closed terminating end portions, and the sliding surface and the sliding surface slide on each other at least in such a manner that the first positive pressure generation grooves and the second positive pressure generation grooves overlap and intersect with each other.

An improved face seal may comprise a seal housing having an annular extrusion, and a primary seal coupled to the seal housing. The primary seal comprises a sealing face and a base opposite the sealing face, wherein the primary seal has an annular structure coaxial with the annular extrusion with the base proximate a first end of the seal housing. The sealing face comprises a disrupted surface.

Provided is a sealing device that increases the lubricity of seal surfaces, prevents leakage of sealed fluids, and prevents excessive heat generation and excessive friction at seal surfaces. Said sealing device, which is of the type that seals a fluid trying to leak from the outer periphery of a sealing surface towards the inner periphery thereof, forms at least two dimples in a circumferential direction in each of a plurality of rows arranged in a radial direction on a sealing surface of a stationary-side sealing element or a rotating-side sealing element. Each dimple is tilted by a dimple angle θ between 0° and 90°, exclusive, such that the tip of that dimple in the direction of rotation is tilted toward the inner periphery side. In each of the plurality of rows of dimples, land areas are formed in the circumferential direction between the proximate tips of adjacent dimples. For each of the plurality of rows of dimples, if a circle is drawn through the centers of the dimples in that row, let L1 be the distance along the circle from the point the circle enters a dimple to the point the circle leaves that dimple, and let L2 be the length, along the circle, of the land areas between dimples. The dimples are characterized by being arranged such that the gap ratio L1/L2 is between 0.001 and 0.1, inclusive.

By randomly arranging dimples provided on a sealing face, a sliding characteristic is improved in a wide range of a bearing characteristic number on the sealing face. A pair of sliding parts in which a plurality of dimples is arranged on at least one of sealing faces that relatively slide on each other is characterized in that each of the plurality of dimples is provided independently from the other dimples, and arranged in such a manner that the plurality of dimples having different opening diameters is randomly distributed.

Low-torque sliding components have sliding surfaces rotated relative to each other with an annular mating ring and an annular seal ring facing each other. The sliding surface of at least one of the mating ring and the seal ring has therein a plurality of multi-stepped recess portions formed in a circumferential direction. Relative rotation and sliding of the mating ring and the seal ring causes the multi-stepped recess portions to generate a dynamic pressure, and the multi-stepped recess portion is formed in a stepwise shape in a cross-sectional view by a dynamic pressure recess portion and a static pressure recess portion with the dynamic pressure recess portion surrounding the static pressure recess portion deeper than the dynamic pressure recess portion.

A sliding component, which achieves both sealing and lubrication by preventing cavitation from occurring in the dynamic-pressure generation mechanism and thereby solving the problem of leakage that will otherwise result from such cavitation, is characterized in that, on a sealing face of one of a pair of sliding parts that slide against each other, extremely shallow grooves constituting a Rayleigh step mechanism are provided in a manner facing the high-pressure fluid side of the sealing face, while deep fluid-introduction grooves for introducing the high-pressure fluid are provided on the upstream side of the extremely shallow grooves in a manner continuing to the high-pressure fluid side.

In an exemplary embodiment, a pair of sliding components has sliding surfaces that slide with respect to each other, wherein at least one of the sliding surfaces, sliding surface S, includes a random dimple group 11 in which plural dimples 10 are randomly arranged, and the random dimple group 11 is arranged to be biased in the circumferential direction of the sliding surface S. The sliding components have an improved lubricating property and reliability of a sealing property.